6431732

Appears in sequences

• Numbers k such that k and k+1 have the same number and sum of divisors.at n=27A054004
• Numbers k such that t(k) = t(k+1) where t(k) = tau(k) + sigma(k) = A007503(k) is the number of subgroups of the dihedral group of order 2k.at n=28A322256